Cartridge magazine with shoulder retention features

ABSTRACT

A magazine configured to receive a plurality of cartridges includes a front portion, a rear portion, and opposing lateral portions between the front portion and the rear portion, the opposing lateral portions including a neck portion, a shoulder portion adjacent the neck portion, and a base portion adjacent the shoulder portion, wherein the neck portion adjacent the shoulder portion has a width that is about 0.005 inches to about 0.04 inches greater than the nominal size of a neck portion of the cartridges.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 12/190,401 filed Aug. 12, 2008 and entitled“Firearm Stock Features,” which is a utility of U.S. Provisional PatentApplication Ser. No. 61/025,242 filed Jan. 31, 2008, which are herebyincorporated by reference in their entirety.

BACKGROUND

1. The Field of the Invention

The present application generally relates to firearms and magazines forfirearms. In particular this application discusses magazines.

2. The Relevant Technology

Modern firearms make use of cartridges that include a projectile seatedin a casing. The casing has an internal cavity defined therein thatcontains a charge of rapidly combusting powder. A primer is seated in arecess formed in a rear portion of the casing. A hole in the primercasing places the primer in communication with the internal cavitycontaining the powder. A projectile is seated in the front portion ofthe casing such that the powder is more or less sealingly contained inthe casing between the primer and the projectile.

An action, such as a bolt action, is used to advance the cartridge intoa firing chamber ahead of firing. While in the firing chamber, a firingpin strikes the primer, causing the primer to ignite. The ignition isdirected to the powder, which burns within the casing. The powder burnswithin the casing generates a rapidly expanding gas. The pressuregenerated by the rapidly expanding gas propels the projectile from thecasing and through the barrel of the firearm. The action can then becycled to remove the empty casing. Cycling the action includeswithdrawing the action from the firing chamber to extract a cartridge,and then advancing the action to position another cartridge within thefiring chamber.

Often a magazine holds additional cartridges such that as the cartridgeis advanced toward the firing chamber, an additional cartridge isautomatically fed into the firing chamber. Such a configuration canallow for relatively rapid feeding of cartridges. A feed rate can befurther enhanced through the use of a detachable magazine, some timesreferred to as a clip. The clip often includes a body that is sized toreceive several cartridges. A spring and follower are positioned withinthe body that maintain the top cartridge in such a position that whenthe clip is attached to the firearm advancing the action feeds acartridge into the firing chamber as discussed above.

The range and accuracy with which a firearm shoots the projectile candepend on a number of factors. Accuracy is often measured by the areaover which projectiles impact a target. Factors that affect accuracy caninclude, among others, variable forces on the barrel, variations of theposition of cartridges relative to the firing chamber and/or relative tothe barrel, variations in the powder charge, the seating force betweenthe projectile and the casing, and the orientation and position of theprojectile relative to the casing. To maximize range, relatively largecharges of powder are used to propel relatively heavy projectiles.

In order to maximize accuracy, especially with cartridges for long rangeshooting, variation is minimized from cartridge to cartridge and fromshot to shot. One approach is to use cartridges loaded in a carefullycontrolled manner. By reducing variation and using large powder chargesand heavy projectiles, accurate shots of more than 1,000 yards arepossible. While providing for accuracy at long ranges, the recoilassociated with large powder charges and heavy projectiles generatessignificant recoil can be significant.

Often, the recoil can be sufficiently violent to cause the front of themagazine to impact the tip of any projectiles in the magazine.Accordingly, to ensure accuracy at long ranges, cartridges are singlefed into the firing chamber instead of using a magazine. While such anapproach can eliminate contact between a cartridge and the magazine, andthus eliminate impact of the magazine with the tip of the projections,single feeding cartridges can increase the possibility that the shooterwill drop a cartridge and thereby negate many of the processes used tomaintain consistency. Further, single feeding can be time consuming andtedious.

The subject matter claimed herein is not limited to embodiments thatsolve any disadvantages or that operate only in environments such asthose described above. Rather, this background is only provided toillustrate one exemplary technology area where some examples describedherein may be practiced.

BRIEF SUMMARY OF THE INVENTION

A magazine configured to receive a plurality of cartridges includes afront portion, a rear portion, and opposing lateral portions between thefront portion and the rear portion, the opposing lateral portionsincluding a neck portion, a shoulder portion adjacent the neck portion,and a base portion adjacent the shoulder portion, wherein a width of theneck portion adjacent the shoulder portion has a width that is about0.005 inches to about 0.04 inches or more greater than the nominal sizeof a neck portion of the cartridges.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential characteristics of the claimed subject matter, nor is itintended to be used as an aid in determining the scope of the claimedsubject matter.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 illustrates a perspective view of a firearm according to oneexample; and

FIGS. 2A-2D illustrates a detachable magazine according to one example.

Together with the following description, the Figures demonstrate andexplain the principles of a magazine configured to reduce jamming and/orprotect a tip of a projectile. In the Figures, the thickness andconfiguration of components may be exaggerated for clarity. The samereference numerals in different Figures represent similar, thoughnecessarily identical, components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Magazines, firearms, and methods of manufacture are provided herein thatallow multiple cartridges to be loaded into a magazine. The magazinesinclude a front wall, a rear wall, and opposing lateral portions betweenthe front wall and the rear wall. The lateral portions include a neckportion adjacent the front wall that is configured interact withcartridges to prevent a tip of the cartridge from impacting the frontwall as the firearm to which the magazine is attached recoils. Forexample, a relatively small clearance can be provided between a neckportion of the magazine and a corresponding neck portion of a casing.The relatively small clearance can help retain a shoulder portion of thecasing during recoil to help prevent the shoulder of the casing fromjamming in the neck portion of the magazine. Accordingly, the magazinecan include a shoulder retention feature. Such a configuration can allowsuccessive cartridges to fed from the magazine while maintaining theinterface between the cartridge's casing and projectile, therebymaintaining consistency. Accordingly, such a configuration can allow forrelatively rapid shots while maintaining accuracy.

FIG. 1 illustrates a firearm 100 that includes a stock 105, a barrel110, an action 115, and a magazine 120. The action 115 is operativelyassociated with the barrel 110. In the illustrated example, a bolt-typeaction is shown. It will be appreciated that in other examples, othertypes of actions, such as pump-type actions, recoil-operated actions,gas-operated actions, as well as any other type of actions can beoperatively associated with any types of actions.

Regardless of the type, cycling of the action 115 moves a cartridge intoposition to be fired and removes the casing after the cartridge has beenfired. For example, forward operation of the action 115 can move acartridge through a breech 125 and into position with the barrel 115.Thereafter, a trigger (not shown) can be actuated to release a firingpin in the action 115. The firing pin strikes a primer, which ignitesgun powder in a casing to propel a projectile through the barrel 110.

Rearward operation of the action extracts the spent casing and moves theaction 115 rearward of the magazine 120. The magazine 120 is coupled tothe stock 105 and is operatively associated with the action 120 and/orthe breech 125 in such a manner that forward operation of the actionmoves a cartridge from the magazine 120 into position with the barrel115. The process can then be repeated until the rounds in the magazine120 are complete.

Thereafter, additional cartridges can be fed into the magazine 120. Inone example, cartridges can be fed through the breech 125 into themagazine 120. In other examples, the magazine 120 can be a detachablemagazine. In such a configuration, cartridges can be fed either throughthe breech 125 or the magazine 120 that can be detached from the stock105. For ease of reference, a detachable magazine will be describedbelow. It will be appreciated that a permanently secured magazine canalso be described.

FIGS. 2A-2D illustrate a detachable magazine 200 with shoulder retentionfeatures according to one example. In the example illustrated in FIGS.2A-2D, the magazine 200 generally includes a front portion 205, opposinglateral portions 210, 215, a rear portion 220, and a base plate 225. Thefront portion 205, the opposing lateral portions 210, 215, and the rearportion 220 define a recess configured to receive a cartridge of aspecified type. The detachable magazine 200 can be configured to receiveany type of cartridge, including, without limitation, .243 Winchester,.308 Winchester, .300 Winchester Magnum, or .338 Lapua Magnum calibercartridges, represented schematically as cartridge 230 in FIG. 2B havinga casing 235 and a projectile 240. As will be discussed in more detailbelow, the detachable magazine 200 is configured to engage and supportthe casing 235 in such a manner to reduce or eliminate contact betweenthe projectile 240 and the front portion 205 of the detachable magazineduring recoil and further help retain the shoulder of the casingrelative to the magazine.

In particular, as illustrated in FIG. 2C when viewed from above theopposing lateral portions 210, 215 have a contour that generallyparallels the profile of a cartridge 230 of the type the magazine isconfigured to house (shown in dashed lines). Accordingly, the lateralportions 210, 215 form a neck portion 245A, a shoulder portion 250A, anda base portion 255A that correspond with a neck portion 245B a shoulderportion 250B, and a base portion 255B of the casing 230 respectively. Aclearance can be selected between the neck portion 245A of the magazineand the neck portion 245B of the casing 230 that retains the shoulderportion 250B of the casing 230 to prevent the shoulder portion 250B fromjamming with the magazine 200 during recoil or other forces. Such afunctionality can be referred to as a shoulder retention feature.

In addition to defining a profile corresponding to the profile of thecartridge 230, the lateral portions 210 define a cavity configured toreceive the cartridge 230. As illustrated in FIG. 2A, part of the upperends of the opposing lateral portions 210, 215 can be configured as lips260, 265 that extend upwardly and inwardly from the opposing lateralportions 210, 215. The detachable magazine 200 can include a followerand biasing member (not shown) configured to urge the cartridges awayfrom the base plate 225 and into engagement with the lips 260, 265.

In order to load cartridges 230 into the detachable magazine 200, thebase portion 245B of a casing 235 is positioned under the lips 260, 265in opposition to a biasing force exerted on the casing 230 by thefollower and biasing member described above. The casing 235 can then bemoved rearward and downward to the loaded position shown in FIGS. 2B-2D,thereby moving the base portion 245B of the casing 235 into proximitywith the rear portion 220 of the detachable magazine 200. Subsequentcartridges 230 can also be loaded into position as shown in FIG. 2B. Acartridge in direct communication with the lips 260, 265 can be referredto as being in a first position while cartridges within the detachablemagazine below the first position can be referred to as being in secondpositions.

As previously introduced, when cartridges 230 are loaded into thedetachable magazine 200, the neck portion 245B, the shoulder portion250B, and the base portion 255B are in proximity with the neck portion245A, the shoulder portion 250A, and the base portion 255A of thedetachable magazine 200. Such a configuration allows the detachablemagazine 200 to retain the shoulder portion 250B of the casing 235 tohelp reduce impact between the front portion 205 of the detachablemagazine 200 and/or help ensure proper feeding of the cartridge 230.

For example, while a cartridge 230 is in one of the second positions, aspace between tips of projectiles 240 and the front portion 205 of thedetachable magazine 200 can help ensure that relative movement betweenthe cartridge 230 and the detachable magazine 200, such as can occurduring recoil, does not result in contact between the projectile 240 andthe front portion 205. For example, the shoulder portion 250A of thedetachable magazine 200 can interact with the shoulder portion 240B ofthe casing 235.

In particular, an internal width of the neck portion 245A of thedetachable magazine 200 corresponds closely to the nominal size of theneck portion 245B of a type of cartridge 230 to be used with thedetachable magazine. For example, the neck portion 245A can have a widththat is approximately 0.005 inches to about 0.04 inches or more greaterthan the nominal size of the neck portion 245B of the casing 235.Further, such a width can have a range that is approximately 0.01 inchesto about 0.025 inches. Accordingly, in the case of a detachable magazineconfigured for use with .338 Lapua Magnum cartridges with a nominaldiameter of 0.372 inches, a neck portion can have a width of betweenabout 0.377 inches to about 0.412 inches, such as a width of betweenabout 0.382 inches to about 0.397 inches. Such clearances can beoptimized for a magazine formed from rolled and stamped steel. Arelatively larger clearance, such as a clearance of greater than 0.04inches to about 0.06 inches or more can be provided so long as theclearance retains the shoulder portion of the casing and prevents theshoulder portion from jamming into the neck portion of the magazine.Accordingly, in some examples clearance between a neck portion of themagazine adjacent the shoulder portion of the magazine can be selectedaccording the material used to form the detachable magazine to therebyreduce or eliminate the potential for a shoulder portion of a casing tobecome jammed in the neck portion of a magazine.

Similarly, in the case of a detachable magazine configured for use with.300 Winchester Magnum cartridges with a nominal diameter of 0.339inches, a neck portion can have a width of approximately 0.344 inches toabout 0.379 inches, such as a width of between about 0.349 inches andabout 0.364 inches. A detachable magazine configured for use with .308Winchester cartridges with a nominal case neck diameter of 0.343 inchescan have a width of approximately 0.348 inches to about 0.383 inches,such as a width of between about 0.353 inches and about 0.368 inches.Further, it will be appreciated that detachable cartridges can beconfigured for use with any type of cartridge as desired.

It has been found that maintaining the width of neck portions withinthis range can help reduce the possibility that cartridges will slipforward in response to forces, such as recoil. Preventing cartridgesfrom slipping forward can reduce or eliminate contact between theprojectile 240 and the front portion 205 of the detachable magazine 200as well as reducing the likelihood that the shoulder portion 250B of thecasing 235 can become wedged into the shoulder portion 250A of thedetachable magazine 200 thereby reducing the likelihood of miss-feedsand thus providing shoulder retention.

The neck portion 245A of the detachable magazine 200 can have the widthdescribed above for any desired length within the detachable magazine,including the entire height, a partial height, or any other combinationof heights. Accordingly, the detachable magazine 200 is configured tocarry several cartridges in such a manner as to reduce or eliminatecontact between a cartridge's projectile and a front portion of thedetachable magazine while preventing the cartridge from being wedgedinto some portion of the detachable magazine. While a cartridge orcartridges 230 are thus loaded in the detachable magazine 230, the lips260, 265 cooperate with the follower and biasing member to maintain acartridge 230 in position to be fed into position in the barrel by anaction. The lips 260, 265 can be positioned and oriented such that partof the base portion 245B of the casing 235 extends above the rearportion 220 of the detachable magazine while a cartridge 230 is in thefirst position described above.

Placing the base portion 245B of the casing 235 in this position allowsan action to engage a cartridge 230 in the first position and cycle thecartridge forward to be fired. As shown in FIG. 2D, the front portion205 of the detachable magazine 200 can include a scalloped upper edge270, which can provide clearance between the front portion 205 and theprojectile 240 as the cartridge 230 is cycled forward.

As the cartridge 230 is cycled forward, the biasing member moves thefollower described above toward the lips 260, 265. If a cartridge is ina second position, the follower moves the cartridge into the firstposition. A spent casing is extracted and ejected by the action as itcycles rearwardly, thereby placing the action in position to loadanother cartridge, thus repeating the cycle.

Accordingly, a plurality of cartridges can be loaded into a detachablemagazine with shoulder retention features. The detachable magazine cansecurely retain the cartridges and help reduce or eliminate impactbetween a projectile and the front portion of the detachable magazinedue to recoil or other forces. The size of the neck portion can beselected to help reduce or eliminate the potential for the neck portionof cartridges from becoming wedged into the corresponding neck portionof the detachable magazine.

In the illustrated example, one or more of the lateral portions 210, 215includes a recess 270 defined therein for receiving a magazine releasemechanism associated with a stock. Accordingly, the detachable magazine200 can be released by selective engagement with the recess 270 and acorresponding tab of a magazine release mechanism. While a detachablemagazine is shown, it will be appreciated that any type of magazine canbe configured as described above. Such magazine types can include fixed,semi-fixed, or any other type of magazine. Further, while operation ofthe magazines has been described with reference to a bolt-actionfirearm, it will be appreciated that a magazine configured as describedabove can be used with any type of action.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges that come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A magazine configured to receive a plurality of cartridges,comprising: a front portion; a rear portion; and opposing lateralportions between the front portion and the rear portion; the opposinglateral portions including a neck portion, a shoulder portion adjacentthe neck portion, and a base portion adjacent the shoulder portion,wherein a width of the neck portion adjacent the shoulder portion has awidth that is about 0.005 inches to about 0.04 inches greater than thenominal size of a neck portion of the cartridges.
 2. The magazine ofclaim 1, wherein the neck portion adjacent the shoulder portion has awidth that is approximately 0.01 inches to about 0.025 inches greaterthan the nominal size of the neck portion of the cartridges.
 3. Themagazine of claim 1, further comprising a base plate on a bottom portionof the magazine; and a follower and a biasing member operativelyassociated with the base plate.
 4. The magazine of claim 1, wherein themagazine is configured as a detachable magazine.
 5. The magazine ofclaim 1, further comprising lips extending inwardly and upwardly fromthe opposing lateral portions.
 6. The magazine of claim 1, furthercomprising a scalloped recess defined in the front portion.
 7. Adetachable magazine configured to receive a plurality of cartridges, thedetachable magazine comprising: a rounded front portion; a rear portion;and opposing lateral portions between the front portion and the rearportion having a profile similar to the profile of the cartridge; theopposing lateral portions including a neck portion, a shoulder portionadjacent the neck portion, and a base portion adjacent the shoulderportion, wherein the neck portion adjacent the shoulder portion has awidth that is about 0.005 inches to about 0.04 inches greater than thenominal size of a neck portion of the cartridges.
 8. The magazine ofclaim 7, wherein the neck portion adjacent the shoulder portion has awidth that is approximately 0.01 inches to about 0.025 inches greaterthan the nominal size of the neck portion of the cartridges.
 9. Themagazine of claim 1, further comprising lips extending inwardly andupwardly from the opposing lateral portions.
 10. The magazine of claim1, further comprising a scalloped recess defined in the front portion.11. A firearm, comprising: a stock having a fore-end and a butt-end; amagazine operatively associated with the stock and being configured toreceive a plurality of cartridges, the magazine including a frontportion, a rear portion, and opposing lateral portions between the frontportion and the rear portion; the opposing lateral portions including aneck portion, a shoulder portion adjacent the neck portion, and a baseportion adjacent the shoulder portion, wherein the neck portion adjacentthe shoulder portion has a width that is about 0.005 inches to about0.04 inches greater than the nominal size of a neck portion of thecartridges.
 12. The magazine of claim 11, wherein the neck portionadjacent the shoulder portion has a width that is approximately 0.01inches to about 0.025 inches greater than the nominal size of the neckportion of the cartridges.
 13. The magazine of claim 1, furthercomprising a base plate on a bottom portion of the magazine; and afollower and a biasing member operatively associated with the baseplate.
 14. The magazine of claim 11, wherein the magazine is configuredas a detachable magazine.
 15. The magazine of claim 11, furthercomprising lips extending inwardly and upwardly from the opposinglateral portions.
 16. The magazine of claim 11, further comprising ascalloped recess defined in the front portion.